Altering Cardiac Cell Fate for Heart Repair

摘要 直接心脏重编程作为心力衰竭的一种新疗法具有很大的前景， 通常由大量功能性心肌细胞的不可逆损失引起的疾病。通过利用 2012年，我在博士和博士后培训期间获得了发育和干细胞生物学方面的知识， 证明在鼠急性心肌梗塞模型中，三种转录因子，Gata 4， Mef 2c和Tbx 5（GMT）将心脏成纤维细胞（CF）转化为功能性诱导心肌细胞（iCM）， 与周围心肌电和机械整合，导致功能改善， 疤痕大小减少。这些发现表明iCM重编程是再生心脏的有效手段 心脏病患者的体内组织。然而，由于人们对这一问题知之甚少， 的因素，使CF被重新编程，心脏重编程的适用性是有限的背景下， 在那个时候，它被尝试过。自从我独立以来，我自己的实验室已经建立了强大的 鼠和人iCM重编程系统。通过使用这些系统，我们获得了对 小鼠iCM的转录、转录后和表观遗传调控（由R 01 HL 128331支持 作为ESI）和人iCM重编程（由R 01 HL 144551支持），并同时提高了质量 和iCM的产率。此R35 EIA申请是对这两个目前资助的NHLBI R 01赠款的扩展， 进一步阐明iCM转化的分子机制，以测试非- 急性损伤的心脏，并利用最新的单细胞多组学和数学建模， 和个性化的重新编程。成功完成这一建议将有助于直接推动心脏 重编程更接近其临床应用，提供了新的见解，分子机制， 心脏细胞命运的确定，并为该领域利用模型和平台开辟新的机会 我们将在这里发展研究其他心血管生理和病理过程。

Abstract Direct cardiac reprogramming holds great promise as a novel therapy for heart failure, a common and morbid disease that is usually caused by irreversible loss of massive functional cardiomyocytes. By leveraging the knowledge in developmental and stem cell biology gained during my PhD and postdoc training, in 2012 I demonstrated that in a murine acute myocardial infarction model, delivery of three transcription factors, Gata4, Mef2c and Tbx5 (GMT) converted cardiac fibroblasts (CFs) into functional induced cardiomyocytes (iCMs) that integrated electrically and mechanically with surrounding myocardium, resulting in functional improvement and scar size reduction. These findings suggest that iCM reprogramming is an effective means of regenerating heart tissue in vivo for human patients with heart disease. However, because relatively little was known about the factors that allow CFs to be reprogrammed, the applicability of cardiac reprogramming was limited to the context in which it had been attempted at that time. Since my independence, my own laboratory has established robust murine and human iCM reprogramming systems. By using these systems, we obtained novel insights into the transcriptional, post-transcriptional and epigenetic regulation of both murine iCM (supported by R01HL128331 as ESI) and human iCM reprogramming (supported by R01HL144551), and concomitantly improved the quality and yield of iCMs. This R35 EIA application is an extension to these two currently funded NHLBI R01 grants to further unravel the molecular mechanisms underlying iCM conversion, to test in vivo iCM reprogramming in non- acutely injured hearts and to exploit the latest single cell multi-omics and mathematical modeling for optimized and individualized reprogramming. Successful completion of this proposal will help to move direct cardiac reprogramming closer to its clinical application, provide new insights into molecular mechanisms underlying cardiac cell fate determination, and open new opportunities for the field to leverage the models and platforms we will develop here to study other cardiovascular physiological and pathological processes.